Atypical Hemolytic Uremic Syndrome Presenting with Diffuse Alveolar Hemorrhage: A Rare Extra-Renal Manifestation.

We report the case of a 72-year-old male patient with chronic kidney disease (CKD) who presented with diarrhea and subsequently developed thrombotic microangiopathy (TMA) and diffuse alveolar hemorrhage (DAH). Diagnostic workup and clinical course led to a final diagnosis of atypical hemolytic uremic syndrome (aHUS). The patient responded to plasmapheresis and corticosteroid therapy. This case highlights a rare presentation of aHUS with DAH in a patient with pre-existing CKD, and the importance of prompt recognition and multidisciplinary management.